Tocilizumab Tocilizumab, also known as atlizumab, is a recombinant humanized, anti-human monoclonal antibody (mAb) of the immunoglobulin G1κ subclass directed against soluble and membrane-bound interleukin-6 (IL-6) receptor (IL-6R) which plays an important role in immune response and is implicated in the pathogenesis of many diseases, such as autoimmune diseases, multiple myeloma and prostate cancer.